1. Field of the Invention
The present invention relates to a method of manufacturing an ion flow recording head, which comprises a corona ion source and an ion flow controller, controls an ion flow generated by the corona ion source by the ion flow controller to obtain a large number of small recording ion flows, and performs desired ion flow recording on a recording medium by these small recording ion flows.
More particularly, the present invention relates to a method of manufacturing an ion flow recording head comprising an ion flow controller in which a first electrode, a first insulating layer, a second electrode, a second insulating layer, and a third electrode are stacked in the order named, two of the first to third electrodes are formed to comprises a plurality of segment electrodes which extend in directions to cross each other, and ion flow passage holes are formed to extend through cross point portions where the electrodes cross each other.
2. Description of the Related Art
A basic arrangement of an ion flow recording head is known to those who are skilled in the art, as disclosed in U.S. Pat. No. 3,689,935. The known ion flow recording head comprises an ion flow controller formed as follows. That is, the ion flow controller has a pair of segment electrodes which oppose each other in a matrix pattern to sandwich a dielectric member formed of an insulating layer therebetween. An ion flow passage hole is formed to extend through a cross point portion where the segment electrodes cross each other. When a voltage to be applied to the pair of segment electrodes is controlled, an ion flow generated by a corona ion source comprising, e.g., a corona wire is controlled, thereby performing desired ion flow recording on an electric charge carrier recording medium such as an electrostatic recording paper sheet.
The ion flow recording head with this structure performs recording by modulating an ion flow flowing through the ion flow passage hole. In addition to the above-mentioned basic structure, an ion flow recording head in which an ion flow passage hole formed in an ion-source side electrode and an insulating layer has a larger diameter than that of an ion flow passage hole formed in an opposite-side electrode and an insulating layer to converge an ion flow, is also known, as disclosed in Published Examined Japanese Patent Application No. 61-8424. The present inventors proposed an ion flow recording head added with a means for converging an ion flow to attain a higher density like in the above-mentioned reference. This head was filed in Japanese Patent Application No. 1-055487 and Japanese Patent Application No. 2-057356 having the former application as a prior application and filed to acquire priority in Japan.
As a means for forming holes in an ion flow controller, a hole working means such as chemical etching, use of a microdrill, use of a punching mechanism, or the like may be applied. However, it is not always easy to apply such a hole working means.
As one notable hole working means, a means for dissolving and removing an insulating layer upon radiation of an excimer laser beam using an electrode pattern as an exposure mask is known, as disclosed in Japanese Patent Application No. 63-255225 previously filed by the present applicant. However, the above-mentioned hole working means can be only marginally satisfactorily applied to a single-layered head material, and it is difficult to apply this means to a multilayered head material in which a large number of insulating layers and a large number of electrode layers are stacked.
The difficulty of application is caused for the following reason. More specifically, in order to obtain segment electrodes, a portion having no electrode members is present between the segment electrodes arranged parallel to each other. Therefore, although ion flow passage holes are to be formed, when an excimer laser beam is radiated on an insulating layer in a gap portion where no electrode members are present, holes are undesirably formed in this portion. In order to prevent this, the gap portion between the electrodes, i.e., a portion where the insulating layer is exposed must be satisfactorily masked by a mask member. However, it is very difficult to precisely mask the micropatterned gap portion in practice.
As examples of multilayered structures in which respective layers are patterned, semiconductor circuit elements, multilayered printed circuit boards, and the like are known. However, there are nearly no examples having a unique pattern and structure, i.e., in which through holes locally have different diameters, and the opening diameters fall within a range of several tens of microns to several hundreds of microns upon completion of a structure like in an ion flow controller. Therefore, in the manufacture of an ion flow recording head having the above-mentioned structure, even if conventional working methods are combined, it is almost impossible to directly apply these methods. Therefore, a conventional inefficient working method must be employed. For this reason, an ion flow controller cannot be efficiently manufactured, thus preventing realization of an ion flow recording head, in particular, a high-speed ion flow recording head. In addition, it is difficult to reduce cost.